Among concerns for generally immobile persons are medical conditions that form blood clots, such as deep vein thrombosis (DVT) and peripheral edema. Such patients and persons include those undergoing surgery, anesthesia, extended periods of bed rest, etc. These blood clotting conditions generally occur in the deep veins of the lower extremities and/or pelvis. These veins, such as the iliac, femoral, popliteal, and tibial veins, return deoxygenated blood to the heart. When blood circulation in these veins is retarded due to illness, injury, or inactivity, there is a tendency for blood to accumulate or pool. A static pool of blood may lead to a blood clot, which can interfere with cardiovascular circulation. More seriously, the blood clot can break loose and migrate. A pulmonary embolus, which may be life threatening, can form if the blood clot blocks a pulmonary artery.
Conventional vascular compression systems include a compression garment fluidly connected to a controller that cyclically inflates the compression garment. The cyclical inflation of the compression garment enhances blood circulation and decreases the likelihood of DVT. A system of conduits connects the compression garment to the controller. Newer vascular compression garments may have portable controllers that are much smaller and mountable on the compression garment allowing the patient to move about freely without first removing the compression garment or disconnecting the compression garment from its controller. These newer compression garments may be worn when a patient is stationary or ambulatory and are believed to enhance patient compliance due to convenience of use.
Active compression garments for applying intermittent compression therapy to a body part (e.g., a limb such as a leg) have many applications, including DVT prophylaxis, edema prevention, and wound healing. The performance of compression garments is dependent upon the ability of the garment to retain its initial fit or tightness so the inflatable bladders retain their original position around the body part. This can be very difficult if the compression garments are used when the patients are in certain positions (e.g., non-horizontal positions) or when the patients are moving. The garments tend to loosen around the body part and/or slide down the body part, causing misalignment of inflatable bladders with corresponding body parts, potentially resulting in ineffective compression therapy and/or discomfort. The present invention is directed to maintaining the inflatable bladders in position on the body part to improve applied compression therapy by increasing the efficiency of the compression therapy. In addition, the present invention is directed to reducing an internal volume of one or more bladders on a compression garment, thus reducing an amount of gas required to inflate the bladders.